Final answer:
Motivation is not a stage in IS development. The stages include Inception, Construction, and Retirement.
Step-by-step explanation:
The stage of IS development that is not part of its lifecycle is C. Motivation. The stages of Information Systems development typically include Inception, where the project is defined or initiated; Construction, where the actual development of the software takes place; and Retirement, where the system is phased out of use. Motivation is not a recognized phase in the Information Systems development process.